2011 Annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 29th Annual Report.

Background: This is the 29th Annual Report of the American Association of Poison Control Centers' (AAPCC) National Poison Data System (NPDS). As of 1 July 2011, 57 of the nation's poison centers (PCs) uploaded case data automatically to NPDS. The upload interval was 8.43 [6.29, 13.7] (median [25%, 75%]) minutes, creating a near real-time national exposure and information database and surveillance system.

Methodology: We analyzed the case data tabulating specific indices from NPDS. The methodology was similar to that of previous years. Where changes were introduced, the differences are identified. Poison center cases with medical outcomes of death were evaluated by a team of 38 medical and clinical toxicologist reviewers using an ordinal scale of 1-6 to assess the Relative Contribution to Fatality (RCF) of the exposure to the death.

Results: In 2011, 3,624,063 closed encounters were logged by NPDS: 2,334,004 human exposures, 80,266 animal exposures, 1,203,282 information calls, 6,243 human confirmed nonexposures, and 268 animal confirmed nonexposures. Total encounters showed an 8.3% decline from 2010, while health care facility exposure calls increased by 4.8%. Human exposures with less serious outcomes decreased by 3.4% while those with more serious outcomes (moderate, major or death) increased by 6.8%. All information calls decreased by 17.9% and health care facility (HCF) information calls decreased by 2.9%, Medication identification requests (Drug ID) decreased by 24.1%, and human exposures reported to US poison centers decreased by 2.2%. The top 5 substance classes most frequently involved in all human exposures were analgesics (11.7%), cosmetics/personal care products (8.0%), household cleaning substances (7.0%), sedatives/hypnotics/antipsychotics (6.1%), and foreign bodies/toys/miscellaneous (4.1%). Analgesic exposures as a class increased most rapidly (10,134 calls/year) over the last 11 years. The top 5 most common exposures in children aged 5 years or less were cosmetics/personal care products (14.0%), analgesics (9.9%), household cleaning substances (9.2%), foreign bodies/toys/miscellaneous (6.9%), and topical preparations (6.6%). Drug identification requests comprised 59.5% of all information calls. NPDS documented 2,765 human exposures resulting in death with 1,995 human fatalities judged related (RCF of 1-Undoubtedly responsible, 2-Probably responsible, or 3-Contributory).

Conclusions: These data support the continued value of poison center expertise and need for specialized medical toxicology information to manage the more severe exposures, despite a decrease in calls involving less severe exposures. Unintentional and intentional exposures continue to be a significant cause of morbidity and mortality in the US. The near real-time, always current status of NPDS represents a national public health resource to collect and monitor US exposure cases and information calls. The continuing mission of NPDS is to provide a nationwide infrastructure for public health surveillance for all types of exposures, public health event identification, resilience response and situational awareness tracking. NPDS is a model system for the nation and global public health.